The Rare-Earth Problem Has a Thorium-Shaped Hole in It
I just returned from two days in Reno, Nevada, where the Army Research Office’s DEVCOM ARO had convened a workshop at the University of Nevada titled “Closing the Gap: Research Priorities for U.S. REE Supply Chain Resilience.” Researchers from Idaho National Laboratory, Lawrence Livermore, Colorado School of Mines, the University of Minnesota, and the National Academies gathered alongside industry representatives and DoD program managers to map the problem honestly and start identifying where targeted investment could actually move the needle.
It was a good workshop — well-structured, serious, and attended by people who understand the scale of what the United States has allowed to happen to its rare earth supply chain. I was there as a panelist on the Industry and DoD Perspectives session, alongside James Kennedy of CalderaUSA (the Pea Ridge Mine project) and Rick Harrison of Applied Research Associates. I want to use this post to explain what I heard, what I said, and why I think the rare earth challenge and the thorium challenge are two faces of the same problem.
What the Workshop Was About
Rare earth elements — the seventeen metallic elements running from lanthanum to lutetium, plus scandium and yttrium — are embedded in virtually every advanced military and energy system the United States fields or intends to field. Permanent magnets made from neodymium and dysprosium sit at the heart of electric motors, wind turbines, missile guidance systems, and radar arrays. Europium and terbium go into displays and lasers. Lanthanum goes into night-vision optics. Yttrium is critical for certain high-temperature ceramics. There is no practical substitute for most of these elements in their high-performance applications.
The competitive gap with China is severe. China currently controls the dominant share of global rare earth mining, and an even larger share of the separation and processing capacity that turns ore into purified oxides and metals. That concentration was not inevitable — the United States once led in rare earth production — but it is now a fact that every defense planner and supply chain analyst has to work around.
The workshop’s two-day structure reflected the shape of the problem itself. Day one asked “where are we?” — covering exploration and mining in the morning and separation and processing in the afternoon. Day two asked “what should we do?” — moving through research opportunity identification and then into parallel breakout tracks on mining, processing, and cross-cutting themes like workforce, permitting, and DoD procurement.
Rod Eggert of the Colorado School of Mines’ Critical Materials Innovation Hub framed the strategic landscape in the opening keynote. The message was not comfortable: the gap between where we are and where we need to be is large, and the timeline for closing it — if we start now — is long.
The Thorium Connection
I was there because Flibe Energy’s work sits at an unusual intersection of the rare earth problem and the nuclear energy problem. Let me explain why.
Rare earth elements occur geologically in association with thorium. This is not a coincidence — both rare earths and thorium concentrate in similar mineral assemblages, particularly in carbonatites and monazite-bearing sands. When you mine rare earths, you get thorium as a byproduct. This has been true for decades, and it has created a perverse regulatory situation that shapes the entire domestic rare earth industry.
Because thorium is mildly radioactive, the Nuclear Regulatory Commission regulates thorium-bearing process streams under its radioactive materials licensing framework. This means that a rare earth processing facility that generates thorium-bearing residues faces NRC licensing requirements on top of the already substantial environmental permitting burden under EPA and state agencies. The combined regulatory load is significant, and it has been a genuine deterrent to domestic rare earth processing investment.
The practical consequence is that some potential rare earth deposits in the United States have not been developed, and some that have been partially developed have left thorium management as an unresolved liability. The Mountain Pass mine in California — the largest rare earth deposit in the United States — was producing material and sending thorium-bearing waste to a licensed disposal facility until cost and regulatory pressures made the operation noncompetitive. It has since been restarted under different ownership, but thorium disposition remains part of the economic calculus.
Here is what I said in the panel, and what I believe: the thorium that comes out of rare earth processing is not a liability to be disposed of. It is an energy resource of extraordinary value. If the United States had a commercial pathway for thorium — which means, concretely, if liquid-fluoride thorium reactors were moving through the regulatory pipeline toward deployment — the thorium produced as a byproduct of domestic rare earth mining would be an asset, not a cost. The economics of rare earth mining would look different. The reluctance to develop thorium-bearing deposits would have less force. The United States would be turning one supply chain problem into a solution for another.
James Kennedy, who has been working for years to develop the Pea Ridge iron ore mine in Missouri as a rare earth resource, made similar points. Pea Ridge has rare earth potential but also has thorium associated with its deposit. Kennedy has argued persistently — and I think correctly — that the regulatory treatment of thorium as pure waste has distorted the economics of domestic rare earth development in ways that have systematically benefited Chinese producers who face no such constraints.
What Needs to Happen
The separation and processing sessions on day one brought home how much work remains between geological resources and usable materials. Michael Free from the University of Utah walked through the hydrometallurgy and solvent extraction landscape. The University of Minnesota group presented promising results on using nonthermal plasma to reduce rare earth chlorides — an elegant approach that could offer energy-efficient recovery at scale. The afternoon panel on scaling from lab to industrial capacity, with Alexa Schmitz of REEgen and Scott McCall from Lawrence Livermore, was direct about the valley of death between research and commercial-scale processing.
The cross-cutting issues on day two — workforce, permitting, international competition, DoD procurement — are where policy levers come in. Deborah Glickson from the National Academies and Cayle Bradley from DoE ARPA-E both pointed to federal funding mechanisms and allied-nation models as sources of lessons. Australia, Canada, and Estonia have all made deliberate policy choices to develop domestic rare earth capacity that are worth studying.
But here is what I want this community to take from my participation at this workshop: the nuclear policy question and the rare earth policy question need to be addressed together. As long as thorium has no commercial pathway — no licensed reactor design, no established fuel cycle, no NRC framework for liquid-fluoride reactors — it will continue to be treated as a radioactive nuisance in the rare earth supply chain rather than as the energy resource it is.
The United States is sitting on thorium in phosphate processing tailings in Florida, in rare earth byproducts in the Mountain Pass waste streams, and in the potential output of deposits like Pea Ridge. The country is simultaneously worried about where its energy will come from to power data centers and defense manufacturing, and worried about where its rare earth materials will come from to build the magnets those systems require. The liquid-fluoride thorium reactor is the technology that converts the first worry into a partial answer to the second.
A Final Note
Workshops like this one matter. Getting the right people in the same room — geologists, chemists, process engineers, DoD program managers, and industry representatives — and structuring the conversation around what is actually broken and what would actually move the needle is more valuable than most of what passes for policy engagement in Washington. The Army Research Office deserves credit for funding it and for taking the supply chain resilience problem seriously at the research level.
But research alone will not close the gap. It will take deliberate choices to treat thorium as an asset, to build the regulatory pathway for advanced nuclear technologies that use it, and to connect the rare earth supply chain problem to the energy production problem in a way that lets each help solve the other. Those choices are available. The physics and the geology are on our side. What has been missing is the institutional will to put them together.
That is what Flibe Energy is working on. And it is why I keep showing up at workshops like this one.